This protocol is designed to meet an unmet need in neuro-oncology by evaluating patients with CNS tumors throughout their disease course. The protocol will evaluate patients with tumors of the central nervous system (CNS) who appear to be probable candidates for future protocol entry, have disease manifestations that are of unique scientific interest, importance, and/or educational value, or who have understudied tumors with unknown or unclear natural history. Patients with known genetic syndromes at high risk of developing CNS cancers will also be evaluated.